Correlating CFD Simulation With Wind Tunnel Test for the Full-Scale UH-60A Airloads Rotor

Data from the recent UH-60A Airloads Test in the National Full-Scale Aerodynamics Complex 40- by 80- Foot Wind Tunnel at NASA Ames Research Center are presented and compared to predictions computed by a loosely coupled Computational Fluid Dynamics (CFD)/Comprehensive analysis. Primary calculations model the rotor in free-air, but initial calculations are presented including a model of the tunnel test section. The conditions studied include a speed sweep at constant lift up to an advance ratio of 0.4 and a thrust sweep at constant speed into deep stall. Predictions show reasonable agreement with measurement for integrated performance indicators such as power and propulsive but occasionally deviate significantly. Detailed analysis of sectional airloads reveals good correlation in overall trends for normal force and pitching moment but pitching moment mean often differs. Chord force is frequently plagued by mean shifts and an overprediction of drag on the advancing side. Locations of significant aerodynamic phenomena are predicted accurately although the magnitude of individual events is often missed.

[1]  William G. Bousman,et al.  Flight Testing the UH-60A Airloads Aircraft , 1994 .

[2]  Mark Potsdam,et al.  Rotor Airloads Prediction Using Loose Aerodynamic/Structural Coupling , 2004 .

[3]  Hyeonsoo Yeo,et al.  Investigation of Rotor Performance and Loads of a UH-60A Individual Blade Control System , 2010 .

[4]  William I. Scallion,et al.  CFD Approaches for Simulation of Wing-Body Stage Separation , 2004 .

[5]  Wayne Johnson,et al.  Technology Drivers in the Development of CAMRAD II , 1999 .

[6]  Peter F. Lorber,et al.  Aerodynamic Results of a Pressure-Instrumented Model Rotor Test at the DNW , 1991 .

[7]  Thomas R. Norman,et al.  Rotor Performance of a UH-60 Rotor System in the NASA Ames 80- by 120-Foot Wind Tunnel , 2004 .

[8]  Thomas R. Norman,et al.  Full-Scale Wind Tunnel Test of the UH-60A Airloads Rotor , 2011 .

[9]  Hyeonsoo Yeo,et al.  Assessment of Comprehensive Analysis Calculation of Airloads on Helicopter Rotors , 2005 .

[10]  W. R. Johnson,et al.  The Prediction of Transonic Flows on an Advancing Rotor , 1986 .

[11]  M. Potsdam.  Dynamic rotorcraft applications using overset grids , 2005 .

[12]  Hossein Saberi,et al.  CFD and CSD Coupling Algorithms and Fluid Structure Interface for Rotorcraft Aeromechanics in Steady and Transient Flight Conditions , 2006 .

[13]  Hyeonsoo Yeo,et al.  Performance Analysis of a Utility Helicopter with Standard and Advanced Rotors , 2004 .

[14]  Hyeonsoo Yeo,et al.  Prediction of Rotor Structural Loads with Comprehensive Analysis , 2008 .